This invention relates generally to metallic resilient seals used primarily for high pressure and/or high temperature sealing applications (e.g., extreme environments). More particularly, this invention relates to metal spring energized seals which contain multiple energizing metal springs retained within a resilient annular metallic jacket having a cross-section with at least two convolutions. One each of these springs is retained by each convolution of the jacket.
Resilient serpentine or convoluted seals are well known in the art. In general such prior art metal seals are comprised of resilient metal capable of high "spring-back". Spring-back is defined as the amount a seal will rebound after the seal has been compressed between sealing cavities or glands. Examples of such resilient convoluted metal seals are represented by the metal seals sold under the trademark Metal-E-Rings by Advanced Products of North Haven, Conn.
However, a major drawback to such well known prior art convoluted seals (i.e., Metal-E-Rings seal) is that although the convoluted seal has very favorable spring-back characteristics, such convoluted seals exhibit a bi-directional pressure ceiling which is quite limited. Also, the prior art convoluted seal has relatively low bearing (i.e., sealing) contact/seating stresses. In addition, the pressure capability of known serpentine seals is quite limited.
A metal seal commonly referred to as a "C-Ring" has a C-shaped cross section. While such C-ring metal seals are excellent for high pressure sealing, these seals unfortunately have low spring-back characteristics. In one variation, a coiled metal spring is provided in the C-shaped jacket to define a spring energized seal. However, while these prior art spring energized seals exhibit improved spring back relative to simple C-ring seals, such spring energized C-shaped seals are problematic in that to achieve the resiliency of the serpentine seal would necessitate the cross/sectional diameter of the seal to be excessively large and in practice, difficult to accommodate (i.e., the seal cavity).